powdrhound

I've never had my car on a dyno as I've never been concerned much with power numbers. I finally got my car on the rollers for the first time today. My engine is getting pulled Monday for a rebuild (it's that time) and we wanted to get a baseline number to see where we are at. My engine originally came stock with a RUF ECU and RUF K24/26 turbos. A year ago I swapped both to Kevins UMW turbos and ECU. The engine was dynoed with the following bolt ons:

UMW K16/997GT2 Zero Clearance Turbos with UMW waste gates
UMW Injectors
UMW road course programming 91 octane tune (1.25bar)
RUF Intake manifold and turbo intake hoses
RUF Exhaust
997GT2RS Intercoolers
Bailey DV30 diverters

Car is RWD

Dyno conditions were as follow:
DynoJet 248 Chassis dyno (RWD)
68ºF
8% humidity
5344' elevation

We had fans on the front radiators but unfortunately did NOT have any fans on the intercooler duct inlets. IATs started at 84ºF prior to the first pull. After the first pull, IATs were 122ºF. We did a second pull where the results were about 15hp less as the ECU no doubt started pulling timing due to heat soaking as the IATs climbed to 164ºF. For comparison, The highest IATs I normally ever see on a road course in 100+ºF weather at the end of a 30 minute session are in the 140s. Fuel used was 91octane with a few gallons of 100 octane mixed in from the last track outing. Effectively, probably 93-94 octane fuel. Dyno pull was performed in 4th gear.

Net results:
Max power: 590.47
Max torque: 631.74

Below is the dyno graph curve which may be of interest to the guys that are running or looking for a track set up. When Kevin built the turbos for me, one of my requirements was a very normally aspirated "feel" to the engine. In other words, I wanted a very gradual build up of torque to make throttle modulation easier on track. Since the engine is operated at or near full power for extended 30 minute sessions, I wanted a set up that would minimize loads and stress on the internals which are currently stock. My motor has over 100 hard track hours right now which is one of the reasons were are breaking it down for a refresh.

Couple of thinks of note. Many people think that K16 based turbos really run out of steam above 6K rpm but that is not necessarily the case. As can be seen by the graph, my set up pulls strongly to redline without let up and max power is actually achieved high up in the power band above 6700rpm. Fuel/Air ratios are right at 12.0 across the board from 3800 to redline.

Each dyno will obviously measure differently and dyno numbers are quite meaningless unless you are using the same dyno in my opinion. Arguing numbers is a moot point generally. For comparison on this exact dyno, my friends stock '07 997GT3 dynoed at 360hp and 380hp with open pipes and an Evoms 100 octane flash. Two different gull wing supercharged Mercedes SLS AMGs spun the rollers there at 483 and 500hp. Later the same day after my car, a 2015 supercharged Z06 dynoed in 20 degree cooler temps at 589.02/613.17. The Z06 is probably the best reliable bench mark for comparison here as it is officially listed by Chevrolet at 650/650 crank so you can draw conclusions from that...

Cheers...

Tuner1

That is a very impressive package of RUF and UMW parts! I might have to look into a pair of those turbos along with Kevin's tuning

Any guesses as to how much the RUF intake set-up helps the spool and/or power?

Could you please post an uncorrected dyno graph? Altitude really messes with the Dynojet's SAE correction factor of FI cars.

You mentioned over 100 track hours on the engine but how many miles total?

Thanks

powdrhound

WSorry, I have no idea on the RUF intake spool up difference versus stock. The car always had the RUF intake on it.

I am really not a Dyno graph expert unfortunately. Like I said, never done a dyno before. That's the only graph that was given to me. I did see that a 2015 Z06 Corvette dynoed later today in 20º cooler temps at 589/613. That's very close and it's a supercharged car. Looks like Chevy officially specs the Z06 at 650/650 which I guess is sea level crank. That is probably the best bench mark to use as it was run on the same roller only a couple of hours after my car. You can probably draw better comparison from that than any dyno chart..

100+ track hours, 50K miles total...

Slalom996T

Impressive numbers powdrhound, both concerning peak values as well as the almost flat part from 4½krpm until 7krpm all including the possble wear from the mileage as well as 100 hrs of track!

I gusss with IC:s sufficiently windcontrolled even flatter with more overall area under the torque curve?

With regards to the IAT I guess the first run was the best?

What was the corrected measured torque number and curve, i.e. without the transmission "tax".

Slalom996T

Tuner1

A Dynojet chassis dyno can't provide this number. For a RWD 911 I would add about 10-12% to guesstimate the crank numbers.

powdrhound, the dyno shop can easily supply the uncorrected numbers if you ask them and it would be nice to see them to understand how the turbos do at elevation. Either way the '15 Z06 numbers certainly confirm that your 996TT is strong.

Slalom996T

Tuner1:

I thought a dynamometer mainly measured torque and rpm since the bhp often is a "consequence" of these variables put into a formula?

How has the transmission "tax" been determined to 10-12%, or any value?

Slalom996T

powdrhound

Gotcha. I'll check with them on Monday and see if they can get those numbers. I'll post them up.

turbo4 me

Slalom,

Did you buy a car yet or are you still theoretical?

Slalom996T

turbo4 me:

Do I understand you correctly when you seem to deem my postings being out of line in a forum titled "Turbo Technical Discussion Areas"?

Do you rather prefer "Which is the best cupholder" or "4 sale" or...?

Slalom996T

turbo4 me

Slalom,

You are a little paranoid- all I asked was whether you bought a car yet-

Actually owing a 996tt is a remarkable experience; you should try it.

jumper5836

I am interested in how internals look for wear once you got the engine apart.

no0one718

nice numbers! those curves look like they want more turbo!!

i'm excited to see what you can do with a built engine. are you changing your turbo setup?

powdrhound

No way..

Scott.

Hahahaha


Awesome numbers John! I'm definitely leaning towards those UMW turbos now..

jumper5836

off topic, but with your setup powdrhound are you able to get two full 30 min sessions out of a tank of gas?